SCENARIO

Water Wise Analytics $($WWA$)$ is a successful and growing organisation carrying out water quality

testing and analysis. WWA is based at a purpose$-$built facility within an industrial unit, on the edge of

a large town with good access to main roads. There are $30$ workers at WWA, mainly consisting of

scientists and technicians working in four different labs. In addition, the organisation has a fieldwork

team. Most days the fieldwork team are out at various sites. Their role is to inspect water sources

and take water samples from numerous locations, bringing these back to the labs for testing. WWA

also has a range of office$-$based support services, including an administration team, IT support,

human resources, and a health and safety team.

There are $4$ purpose$-$built labs, each specialising in different types of testing and analysis. Lab $1$

identifies contaminants in water samples, and where required produces a water treatment plan. This

will be done when the water source needs to be treated so that it is fit for purpose. Lab $4$ is a

microbiology lab specialising in testing for Escherichia coli $($E$.$ coli $0157).$

Each lab has a range of equipment relevant to the type of work carried out, including workbenches

with stools, chemical storage cupboards under the workbenches, fume cupboards, autoclaves,

incubators, and microscopes. Each lab also has its own changing rooms and toilets. The scientists

and technicians are highly trained in their specific work. All scientists and technicians receive

detailed health and safety induction training about their own safe laboratory working procedures.

Laboratory $1($Lab $1)$

In this lab, workers are testing water samples and working on water treatment plans. The treatment

plans often require sodium hypochlorite to be added to water systems at an appropriate dose, and

the lab workers carry out tests to determine the dosing regime required. These tests involve adding

measured amounts of sodium hypochlorite to water samples. The sodium hypochlorite is supplied in

$5$ litre containers that are a manageable size to handle in the lab, and allow relatively small amounts

of sodium hypochlorite $($typically $100-200$mls$)$ to be dispensed safely into measuring cylinders.

Today, worker B finds that the $5$ litre container that is kept in the lab's cupboard is empty, and visits

the stores to collect another. At the stores, worker B is informed that sodium hypochlorite is now

being purchased in a $20$ litre container which is better value for money. The stores' manager shows

worker B the advert in the supplier's catalogue $($see supporting document $1),$ and seems pleased

that they have managed to save the organisation money. They tell worker B that, in future, the $20$

litre container will be delivered straight to the lab, so fewer trips to the stores will be needed.

Worker B$,$ who is now running late on the day's work schedule, returns to Lab $1$ with this much larger

container. They feel quite hot after carrying the $20$ litre container, so push up the sleeves on their lab

coat before putting on their PPE. Remembering their induction training worker B does not want to

decant any of the sodium hypochlorite into an unlabelled container, as this is not good practice.

Instead, they lift up the container and start to pour the required amount directly into the measuring

cylinder on the workbench. Unfortunately, the sodium hypochlorite comes out of the container very

quickly, spilling down the side of the measuring cylinder and onto the workbench. Worker B tries to

stop the measuring cylinder from falling over, and in doing this partly loses their grip on the large

container of sodium hypochlorite. There is now sodium hypochlorite all over the workbench, the

equipment, and on the forearms of worker B$.$ Their colleagues grab the spill kit and rush to assist

worker B$,$ and deal with the spillage.

The next day when Lab $1\text{'}$s manager returns from annual leave, they see the accident report on their

desk. They are concerned that there will be lots of questions raised about the safe working methods

in Lab $1.$ They quickly look at the existing hazardous substance risk assessment for this task, and

the safety data sheet $($SDS$)$ for sodium hypochlorite $($see supporting document $2).$ The lab

manager is thankful that the company$-$wide control system is now in place for hazardous substances.

This also means that they can confirm that all workers at WWA received training in the safe handling

of chemical and biological agents earlier in the year. However, that makes it more surprising to the

manager that this accident happened.